Fluorinated esters and preparation thereof

ABSTRACT

FLUORINE-CONTAINING ESTERS ARE PREPARED BY REACTING A FLUORINATED KETONE WITH AN ALKALI METAL FLUORIDE, AND REACTING THE RESULTING ALCHOLATE INTERMEDIATE WITH AN ACYL HALIDE.

United States Patent 3,637,791 FLUORINATED ESTERS AND PREPARATIONTHEREOF Allen G. Pittman, El Cerrito, and William L. Wasley,

Berkeley, Calif., assignors to the United States of America asrepresented by the Secretary of Agriculture No Drawing. Division ofapplication Ser. No. 704,206, Dec. 28, 1967, now Patent No. 3,465,050,which is a division of application Ser. No. 623,483, Jan. 9, 1967, nowPatent No. 3,419,602, which in turn is a division of application Ser.No. 398,129, Sept. 21, 1964, now Patent No. 3,384,628. Divided and thisapplication May 21, 1969, Ser. No. 826,655

Int. Cl. C07c 69/62, 69/54; D06c 27/00 U.S. Cl. 260-456 R 23 ClaimsABSTRACT OF THE DISCLOSURE Fluorine-containing esters are prepared byreacting a fluorinated ketone with an alkali metal fluoride, andreacting the resulting alcoholate intermediate with an acyl halide.

This is a division of our copending application, Ser. No. 704,206, filedDec. 28, 1967, now Pat. 3,465,050, which in turn is a division of Ser.No. 623,483, filed Jan. 9, 1967, now Pat. 3,419,602, which in turn is adivision of Ser. No. 398,129, filed Sept. 21, 1964, now Pat. 3,384,628.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purpose of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to and has among its objects the provision ofnovel processes for preparing fluorinated compounds, the provision ofthe products as new compositions of matter, and procedures for treatingfibrous materials, especially textiles, with the compounds. Furtherobjects of the invention will be evident from the following descriptionwherein parts and percentages are by weight unless otherwise specified.

In conventional practice, if it is desired to convert a ketone to anester the following procedure is used: The ketone is reduced to analcohol and the alcohol is esterifield with an acid halide. Thus:

Acid halide AGO-CH* (wherein Ac is an acyl radical). It is to beparticularly observed that the conventional procedure requires areduction step and that the ester product contains a hydrogen atom onthe alpha position of the alcohol moiety. (This hydrogen atom isindicated above by an asterisk.) In accordance with the invention,fluorinated esters are prepared from ketones. In a first step, theketone is reacted with an alkali metal fluoride to convert the carbonylradical of the ketone into an alkali metal fluorocarbinolate radical,that is, a fluorocarbinol group wherein the hydrogen of the hydroxylradical is replaced by alkali metal. Thus:

I MF I 3,637,791 Patented Jan. 25, 1972 ice (M being an alkali metal).Then, the intermediate is reacted with an organic acid halide to form anester, as follows:

I Acid halide I MO(llF AGO-(13F wherein Ac is the acyl radical of anorganic acid.

By this simple two-step synthesis, many different kinds of fluorinatedesters can be produced in yields as high as of the theoretical. Thereactions may be further exemplified by the following formula whichdepict the synthesis of heptafluoroisopropyl acrylate fromhexafluoroacetone:

It is evident from the above formulas that the key step in the synthesisis the reaction of the ketone with the alkali metal fluoride. Thisreaction not only changes the ketone function to an alcohol functionwithout requiring use of a reducing agent, but also adds a fluorinegroup which carries over to the ester; that is, the ester contains afluorine group on the alpha carbon atom of the alcohol moiety. This isan unusual type of structure which gives the products especially usefulproperties. For example, the products can be used to provide oilandwater-repellent finishes on textiles and the repellency attained issubstantially greater than that achieved with the correspondingcompounds wherein the same position is occupied by hydrogen.

The process of the invention is by no means limited to the example abovebut is of great versatility and, generically, can be applied to anyaliphatic (open-chain or closed-chain) ketone which contains at leasttwo fluorine group adjacent to the carbonyl group. In other words, thecarbon atoms connected to the carbonyl group must contain at least twofluorine atoms-distributed on these carbon atoms symmetrically orasymmetrically. These fluorine groups are a critical item to activatethe carbonyl group so that it will undergo the desired transformationwhen contacted with the alkali metal fluoride. Especially good resultsare obtained when the carbon atoms adjacent to the carbonyl radicalcontain halogen radicals (i.e., F, Cl, Br, or I) in addition to theminimum of two fluorine groups. In this connection it may be noted thatalthough halogens of higher atomic weight than fluorinei.e., Cl, Br, andI-are not effective by themselves to activate the carbonyl group, theycan be employed to supplement the activating influence of fluorinegroups. Beyond the positions adjacent to the car bonyl group, thestructure of the ketone is of no criticality to the process andavailable sites may be occupied, for example, by hydrogen or halogen. Inother words, the critical item for the process aspect of this inventionis that the starting compound contain a carbonyl group activated byadjacent fluorine atoms as explained hereinabove; the remainder of thestarting compound is not material to the process. Of course, thisremainder may be limited in accordance with certain parameters toprovide particular desired characteristics in the ester products.However, such limitation concerns the character of the ester product,not the operation of the process.

Typical examples of ketones to which the process of the invention may beapplied and the corresponding ester products are given below by way ofillustration but not limitation:

Kctone starting compound) Ester (product) 1 fl 1 F2)n F2)HH H( F2)n-F2)HH u Ac(l) F Fa( 2)n (CF2)nCFa 3 Z)n g (CFZ u CF3 I lie? H(CF:) 2)n FH CF C CF 'F wherein n and n are each a number from 0 to 10 n 2) F 2) rr (CI"3 2CFCCF(CF )2 (CFa)zCF%CF(CF )g II(CFz) CCF(CF3)2H(CFz)n-gCF(CF3)z fl Ac? 0 A00 I CF3(CF2)11 CCF(CF3)1 CF3 (CF2) cF(CF3)2R-CC|1 2n+l RI( 3-C,1F

Wherein n is a number from 0 to 18 Wherein R represents an alkyl groupcontaining 1 to 18 carbon atoms or a cycloalkyl group Such asoyclopropyl, cyclobutyl, or cyclohcxyl. i RCCF(CF3)2 R-'(F CF(CFK)2 20Wherein R re resents the he tail r cl b t l d l p p my 0 u y m m It isalso within the broad scope of the invention to O: m F2) n F2) utilize,as the starting material, k etones containing more U k 1 than onecarbonyl group. By ad ustment of the propor- Wherein n is a number from3 to 10 trons of reactants 1n line with usual stolclnome tricalrelationships, diesters are produced. Typical in this category 1 (A0 isan acyl radical of an organic acid.) are h f ll i Ester (A0 is acylgroup of Kctonc an organic acid) H. r (C F3):C FC-CC F (C F3): (C F )1CF(iJ-(JC F (C F92 F F r i (C F3)2C F C-(C Fz)3CC F (C F )z (C F3)2C FC|1(C Fz) (|J-C F (C F3):

Compounds containing other halogen atoms in addition to fluorine (Y isCl, Br, or 1) A00l Y C FZ(IJC F;

F Ac? YCF2CCF Y ll Yo i i-0431 3 AcO Wherein It is a number from 0 to 18no? C F -(CF h-fi-J) FY:

Wherein 11 is a number from U to 18 Generically, a preferred class ofketones which may be used in the process of the invention and theintermediates and the esters formed therefrom may be represented by thefollowing structures:

(l3) Alkali metal Wherein each R represents a member of the groupconsisting of hydrogen, halogen, alkyl, haloalkyl, cycloalkyl, andhalocycloalkyl and wherein at least two of the Rs are fluorine. Acrepresents an acyl radical of an organic acid. M represents an alkalimetal. The fiuorocarbinolates and the esters responding to the structuregiven above in columns B and C are new compounds, not heretoforeprepared or described.

As noted above, in the first step of the synthesis the finoroketone isreacted with an alkali metal fluoride. As the latter reagent, potassiumfluoride in generally preferred, but the fluorides of sodium, cesium,and rubidium may also be used. The reaction is generally conducted in aninert solvent for the ketone, for example, acetonitrile, dioxane,tetrahydrofuran, tetramethylene sulphone, diglyme (an abbreviated namefor dimethyl ether of diethylene glycol), etc. The alkali metal fluorideis only slightly soluble in these solvents and the disappearance ofundispersed alkali metal fluoride during the reaction supplies a usefulindication of formation of the desired intermediate (which is soluble).The temperature of reaction is not critical. Generally, temperaturesover 35 C. are avoided to prevent decomposition of the intermediate.Usually, the reaction is conducted at room temperature for conveniencebut it does take place at much lower temperatures. Where the startingketone is a gas (for example, hexafluoroacetone) it is preferred to coolthe system first to get the ketone into solution. Then, the temperaturecan be increased-for example, allowed to warm to room temperaturetoaccelerate the reaction. To prevent hydrolysis of the intermediate, thereaction is conducted under anhydrous conditions. It is also helpful toremove air (which may contain moisture) by flushing the reaction vesselwith dry, inert gas such as nitrogen. When the intermediate is frmedasevidenced by disappearance of undissolved alkali metal fluoridethesystem is ready for further treatment. Where the intermediate (thefluorocarbinolate) is intended as the product, it is isolated from thereaction system by evaporating the solvent therefrom under vacuum. Whereit is desired to produce an ester, the intermediate is not isolated butemployed just as it is formed. The esterification is accomplished simplyby adding the desired acid halide and stirring the mixture. Thetemperature is not critical and may range, for example, from 0 to 35 C.No novelty is claimed, per se, in this esterification-it is analogous toconventional esterification by reacting an acid halide with analcoholate.

The ester is recovered from the system by adding water and separatingthe organic phase from the aqueous phase containing dissolved alkalimetal salt. The organic phase may then be dried and the productseparated by distillation. In the alternative, the reaction mixture maybe filtered to remove alkali metal salt and the product isolated bydistillation.

In the esterification step, one can use any desired acid halide.Typically, the acid halide may be a carbonyl halide, a sulphonyl halide,or a haloformate. Compounds which may be used are listed below by way ofillustration and not limitation:

Unsaturated acid halides, for example, compounds of the type:

wherein X is F, Cl, Br, or I and R is H or a lower alkyl radical.

Saturated acid halides, for example, compounds of the typ AlkC-X whereinX is F, Cl, Br, or I and Alk is an alkyl radical containing one to 18carbon atoms.

Aromatic acid halides, for example, benzoyl, toloyl, xyloyl, naphthoyl,anisoyl, dodecylbenzoyl, parachlorobenzoyl, nitrobenzoyl,2,4-dichlorobenzoyl, etc. fluorides, chlorides, bromides, or iodides.

Fluorinated acid halides, for example, compounds of the type:

wherein X is F, Cl, Br, or I and n. has a value from 0 to 18.

Other carbonyl halides such as phenylacetyl chloride, ethoxyacetylchloride, crotonyl chloride, hexahydrobenzoyl chloride, nitrobenzoylchloride, 'acetyl-benzoyl chloride, oleoyl chloride, linoleoyl chloride,chloroacetyl chloride, cinnamyl chloride, phenoxyacetyl chloride, etc.

Aromatic sulphonyl halides, for example, benzene, toluene xylene,naphthalene, anisole, phenetole, dodecylbenzene, nitrobenzene,parachlorobenzene, 2,4-dichlorobenzene, a-toluene, etc. sulphonylfluorides, chlorides, bromides, or iodides.

Saturated aliphatic sulphonyl halides, for example, compounds oi thetype:

CH (CH ),,-SO X wherein X is F, Cl, Br, or I and n has a value from O to18.

Fluorinated aliphatic sulphonyl halides, for example, compounds of thetype:

CF -(CF SO X wherein X is F, Cl, Br, or I and n has a value from 0 to18.

Unsaturated sulphonyl halides, for example, compounds of the type:

CI"I2=CS 02X wherein X is F, Cl, Br, or I and R is H or a lower alkylgroup.

Other sulphonyl halides, for example, cyclohexane sulphonyl chloride,benzyl sulphonyl chloride, etc.

Saturated haloforrnates, for example, compounds of the type:

it AlkO-CX wherein X is F, Cl, Br, or I and Alk is an alkyl radicalcontaining one to 18 carbon atoms.

Aromatic haloformates, for example, compounds of the type:

it Ar-O-CX wherein X is F, Cl, Br, or I and Ar is an aryl radical suchas phenyl, tolyl, xylyl, naphthyl, etc.

Fluorinated haloformates, for example, compounds of the types:

t llCF2-(OF2),,CH2-O X it CF3 (CF2)n CH2 0O X wherein X is F, Cl, Br, orI and n has a value from 0 to 18.

Unsaturated haloformates, typically compounds of the types:

wherein X is F, Cl, Br, or I and R is H or lower alkyl radical.

Although it is generally preferred to utilize monofunctional acidhalides in the esterification, it is within the broad ambit of theinvention to use polyfunctional agents for example, maleyl chloride,malonyl chloride, succinyl chloride, adipyl chloride, itaconyl chloride,benzene disulphonyl chloride, ethylene glycol bis-chloroformate,diethylene glycol bis-chloroformate, the bis-chloroformate 7 of 2,2 bis(parahydroxyphenyl)propane, and the like. Where polyfunctional acidhalides are employed, the proportions of the acid halide and theabove-described intermediate may be selected to attain complete orpartial esterification of the available acid halide sites.

The alkali metal fluorocarbinolates produced in accordance with theinvention are primarly useful as intermediates for the preparation ofesters as herein disclosed.

The esters produced in accordance with the invention may be used in manyareas wherein esters in general are employed, i.e., as lubricants,plasticizers, and hydraulic fluids. Moreover, because of their contentof fluorine, particularly the fluorine atom on the tx-carbon atom of thealcohol moiety, they are useful in such applications as oil and waterrepellents. Thus, by applying solution of these ester to materials suchas paper, fabrics, yarns, etc., these materials will resist thepenetration of oils and water. Of particular utility are the estersderived from acrylic, methacrylic, or other acids containing a CH =Cgroup. These esters are polymerizable and can be formed intohomopolymers or copolymers by conventional polymerization techniques as,for example, heating at about 7085 C. in the presence of a smallproportion of a polymerization initiator such as cx,ot'-21ZO-bisisobutyronitrile. These novel polymers can be used in suchapplications as coating and as adhesives in laminating sheet materials.Of special interest is that the polymers exhibit low solubility incommon solvents such as benzene, toluene, xylene, etc., Whereas they aresoluble in fluorinated solvents such as benzotrifluoride,1,3-bis-trifiuoromethyl benzene, and the like. Thus, the polymers inquestion can be used in coating and adhesive applications where otherpolymeric materials are unsuitable because of solubility in commonorganic solvents.

A particular phase of the present invention is concerned with thetreatment of fibrous materials, such as textiles, in order to improvetheir properties, e.g., to improve their oiland water-repellency. Inapplying this phase of the invention, an ester derived from acrylicacid, methacrylic acid, or other organic acid containing a CH C group isprepared as hereinabove described. This polymerizable ester is thenapplied to the fibrous material, using either of two procedures. In oneprocedure the monomeric ester is applied to the fibrous material andpolymerized in situ thereon by applying ionizing radiation, apersulphate, a peroxide, an azo polymerization initiator, or a redoxcatalyst system (typically, a combination of a reducing agent such ashydrazine sulfate, ferrous sulphate, sodium bisulphite, etc., and anoxidizing agent such as hydrogen peroxide, benzoyl peroxide, sodiumperacetate, etc.). In the preferred procedure, the polymerizable esteris first formed into a polymer and then applied to the fibrous material.The polymer may be a homopolymer, that is, one consisting of recurringunits of the ester, or it may be a copolymer, that is, a polymercontaining recurring units of the ester interspersed with units derivedfrom a different vinyl monomer, such as ethylene, propylene, styrene,vinyl chloride, acrylonitrile, methyl methacrylate or acrylate,acrylamide, methacrylamide, vinyl acetate or stearate, butadiene, andthe like. The polymers are prepared by conventional techniques. Forexample, the polymerizable ester per se or admixed with a differentvinyl monomer is heated at about 70-85 C. in the presence of a smallproportion of a polymerization initiator such asa,a'-azobisisobutyronitrile. As illustrative examples of this procedure,when heptafluoroisopropyl acrylate is formed into a homopolymer, theproduct will be a polymer containing in its skeletal chain recurringunits of the structure:

cut -cnerror-win In the event that thesame ester is copolymerized withbutyl acrylate, for example, the copolymer product will contain in itsskeletal chain recurring units of the above type plus recurring unitsderived from butyl acrylate, i.e.,

In any event, the polymers (homoor co-polymers) are applied to thefibrous material in conventional manner. Typically, the polymer isdissolved in an inert, volatile solventfor example, benzotrifluoride or1,3-bis-trifluorobenzeneand the resulting solution applied to thefibrous material by a conventional dip and pad technique. By varying theconcentration of polymer in solution and the degree of padding, theamount of polymer deposited on the material may be varied. Typically,the amount of polymer may be about from 0.1 to 20%, based on the weightof fibrous material but it is obvious that higher or lower proportionscan be used if desired. Usually, in treating textiles such as fabricsthe amount of polymer is limited to about 0.1 to 10% to attain thedesired repellency improvement without interference with the hand of thetextile. Generally, it is preferred to subject the fibrous material to aconventional curing operation after application of the polymer solutionthereto in order to bond the polymer to the fibers. As an example ofsuch treatment, the fibrous material is heated in the range of about 50to 150 C. for a period of about 5 to 30 minutes. The solvent (from thepolymer solution) may be evaporated in a separate step prior to curingor may be simply evaporated during the curing operation. Fibrousmaterials treated with the polymers of the invention display anincreased resistance to becoming soiled because they repel both waterandoil-borne soils and stains. Moreover, the improvements so rendered aredurable-they are retained despite launder- .ing and dry-cleaning of theproduct.

The invention may be utilized for improving the properties of all typesof fibrous materials, for example, paper, cotton; linen; hemp; jute;ramie; sisal; cellulose acetate rayons; cellulose acetate-butyraterayons; saponified acetate rayons; viscose rayons; cuprammonium rayons;ethyl cellulose; fibers prepared from amylose, algins, or pectins; wool;silk; animal hair; mohair; leather; fur; regenerated protein fibersprepared from casein, soybean, peanut proteins, zein, gluten, eggalbumin, collagen, or keratins; nylon; polyurethane fibers; polyesterfibers such as polyethylene terephthalate; polyacrylonitrile-basedfibers; or fibers of inorganic origin such as asbestos, glass, etc. Theinvention may be applied to textile materials which are in the form ofbulk fibers, filaments, yarns, threads, slivers, roving, top, webbing,cord, tape, Woven or knitted fabrics, felts or other non-woven fabrics,garments or garment parts.

EXAMPLES The invention is further demonstrated by the followingillustrative examples. The various tests described in the examples werecarried out as described below:

Oil Repellency: The 3M oil repellency test described by Grajeck andPetersen, Textile Research Journal, 32, pages 320-331, 1962. Ratings arefrom 0 to 150, with the higher values signifying the greater resistanceto oil penetration.

Water Repellency: AATC spray test, method 22-1952. Ratings are from 0 to100 with the higher values signifying greater resistance to waterpenetration.

Home Laundering Procedure: An agitator-type home washing machine wasoperated under the following conditions. Low water level (about 11 gal);wash temperature, 115-125 F.; rinse temperature, -115 F.; normalagitation; 12-minute wash cycle; load-2 pounds ballast plus samples,total weight not exceeding 4 pounds; cc.

Tide detergent. Washed samples were dried 15 minutes in a forced draftoven at 160 F.

EXAMPLE 1 Preparation of heptafluoroisopropyl acrylate An apparatus wasassembled including a 3-neck flask equipped with thermometer, stirrer,and a reflux condenser cooled with Dry Ice (solid C The open end of thecondenser was connected to a drying tube to prevent ingress of moisturefrom the air. The system was flushed with nitrogen, then 76 g. (0.5mole) dry cesium fluoride and 200 m1. dry diglyme were placed in theflask and mixed. The dispersion was cooled to minus 40 C., by applying aDry-Ice cooling bath to the flask, and 84 grams (0.506 mole) ofhexafluoroacetone was introduced into the flask. The cooling bath wasthen removed and the system allowed to come to room temperature. As thesystem warmed, formation of the fluorocarbinolate intermediate wasevidenced by disappearance of the dispersed CsF, giving a homogeneoussolution.

Acryloyl chloride (41 g., 0.45 mole) was then added with stirring. Aprecipitate formed immediately. Stirring was continued at roomtemperature for /2 hour.

The mixture was poured into 3 volumes of Water. The lower phase wascollected, washed three times with 100- ml. portions of water.Eighty-six grams of crude product was obtained. The product was driedover calcium sulphate, and distilled in vacuo through a short Vigreuxcolumn. Seventy-eight grams of purified productheptafluoroisopropylacrylatewas collected as a clear liquid, B.P. 75.5 C. at 760 mm. of Hg.

Calculated for C FqHgOg (percent): C, 29.99; F, 55.5; H, 1.25. Found(percent): C, 29.42; F, 56.2; H, 1.77.

EXAMPLE 2 Preparation of polymer of heptafluoroisopropyl acrylate A4-gram sample of the ester prepared in Example 1 and 100 mg. of a,x'-azobisisobutyronitrile were heated at 78 C. for 3 hours in a sealedvessel. The polymer was a tacky, colorless solid, soluble inbenzotrifluoride and 1,3- bis-trifluoromethyl benzene.

EXAMPLE 3 Preparation of heptafluoroisopropyl methacrylate CH 0 CF. CHF(/O F (SF. The procedure of Example 1 was repeated, using methacryloylchloride in place of acryloyl chloride. A 70% yield ofheptafluorisopropyl methacrylate was obtained as a clear liquid, B.P.85-86 C. at 760 mm.

EXAMPLE 4 Preparation of polymer heptafluoroisopropyl methacrylate A4-gram sample of the ester prepared in Example 3 and 100 mg. ofa,a'-azobisisobutyronitrile were heated at 78 C. for 3 hours in a sealedvessel. The polymer was a glassy, brittle resin, soluble inbenzotrifluoride and 1,3- bis-trifluoromethylbenzene.

EXAMPLE 5 Preparation of heptafluoroisopropyl acetate CF: oH1i3-0 3F Theprocedure of Example 1 was followed, substituting acetyl bromide for theacryloyl chloride. The amounts of material used were:

Cesium fluoride40 g., 0.26 mole Hexafluoroacetone44 g., 0.26 moleDiglyme (so1vent)--100 ml.

Acetyl bromide19.6 ml., 0.26 mole The product, heptafluoroisopropylacetate, was obtained as a clear liquid in a yield of 32 grams, B.P.6566 C. at 760 mm. Hg.

EXAMPLE 6 Preparation of heptafluoroisopropyl propionate The procedureof Example 1 was repeated, using the following materials:

Potassium fluoride-66 g., 0.114 mole Diglyme (solvent)50 ml.Hexafluoroacetonel8.8 g., 0.113 mole Propionyl chloride9 ml., 0.113 moleThe product, heptafluoroisopropyl propionate, was obtained in a yield of35% as a clear liquid, B.P. 83-84 C. at 760 mm. Hg.

EXAMPLE 7 Preparation of fi-chloro-hexafluoroisopropyl acrylate I? 0CFzCl CH2=CCO I F CFa Using the apparatus described in Example 1, 100m1. of diglyme and 31.3 grams of cesium fluoride were cooled to aboutminus 40 C. and 37.5 g. of monochloropentafluoroacetone (CF COCF CI)were added. The system was allowed to warm to room temperature and whenthe solution had cleared, 14.9 ml. of acryloyl chloride was added andthe system stirred for a half-hour. The ester product was isolated inthe same manner as described in Example 1. Yield 20 grams, B.P. ll2113C. at 760 mm. Hg.

EXAMPLE 8 Polymer of 3-chloro-hexafluoroisopropyl acrylate A 3-gramsample of the acrylate prepared in Example 7 and 50 mg. ofa,a'-azobisisobutyronitrile were heated at 78 C. for 3 hours in a sealedvessel. The polymer was a glassy solid which softened at about 85 C. andwhich was soluble in benzotrifluoride and 1,3-bis-trifluoromethylbenzene.

EXAMPLE 9 Preparation of ,B-chloro-hexafluoroisopropyl methacrylate Theprocedure of Example 7 was repeated, substituting the equivalent amountof methacryloyl chloride for the acryloyl chloride.

The ester product was recovered in a yield of 32 grams, B.P. 123-124 C.at 760 mm. Hg.

EXAMPLE 10 Polymer of B-chloro-hexafluoroisopropyl methacrylate A 4-gramsample of the ester prepared in Example 9 and mg. ofu,a'-azobisisobutyronitrile were heated at 78 C. for 3 hours in a sealedvessel. The polymer was a glassy, brittle solid which softened at about100 C. It was soluble in benzotrifluoride and 1,3 bis trifiuoromethylbenzene.

1 1 EXAMPLE 11 Preparation of 8,,8-dichloro-pentafluoroisopropylmethacrylate ClCFz O CN ClCFg Cesium fluoride (30.4 g., 0.2 mole) wasdispersed in 100 ml. diglyme and the dispersion was cooled to C.1,3-dichlorotetrafluoroacetone (40 g., 0.2 mole) was added with stirringand the mixture allowed to warm to room temperature. After the mixturehad cleared, 20 g. of methacryloyl chloride was added and stirring wascontinued for /2 hour at room temperature.

The mixture was poured into 3 volumes of water and the lower layerseparated, washed with water, dried, and distilled, giving a 32% yield(18 g.) of B,B'-dichloro pentalluoroisopropyl methacrylate, B.P. 156-l57C. at 760 mm. Hg.

EXAMPLE 12 Polymer of [3,5-dichloro-pentafluoroisopropyl methacrylate A4-gram sample of the ester prepared in Example 11 and 75 mg. ofa,oU-azobisisobutyronitrile were heated at 80 C. for 4 hours in a sealedvessel. The polymer was a hard, brittle solid. It was soluble inbenzotrifluoride and 1,3-bis-trifiuoromethyl benzene.

EXAMPLE 13 Preparation of ,H,;i'-dichloro-pentafiuoroisopropyl acrylateThe procedure of Example 11 was repeated, substituting the equivalentamount of acryloyl chloride for the methacryloyl chloride. The esterproduct was obtained in a yield of 32 grams, B.P. 145.5 C. at 760 mm.Hg.

EXAMPLE 14 Polymer of [3,13-dichloro-pentafluoroisopropyl acrylate A4-gram sample of the ester prepared in Example 13 and 75 mg. ofa,a-azobisisobutyronitrile Were heated at 80 C. for 4 hours in a sealedvessel. The polymer was an amorphous, clear solid. It was soluble inbenzotrifluoride and 1,3-bistrifiuoromethyl benzene.

EXAMPLE 15 Preparation of acrylic acid ester of perlluorohaptan-4-o1Cesium fluoride (10.9 g., 0.072 mole) was dispersed in 50 ml. diglymeand the dispersion cooled to 0 C. Perfiuorol1eptan-4-one (26.5 g., 0.072mole) was added with stirring. After formation of the intermediate, 6.48g. of acryloyl chloride was added and stirring was continued for /2 hourat room temperature.

The mixture was poured in 3 volumes of water and the lower layerseparated, washed with water, dried, and distilled. The product, havingthe formula given above, was obtained in a 30-gram yield, B.P. 167 C. at760 mm. Hg.

The product was polymerized in the following manner:

A 4-gram sample of the acrylate and 75 mg. of u,ot'-azobisisobutyronitrile were heated at 80 C. for 4 hours in a sealedvessel. The polymer was a glassy, amorphous solid. It was soluble inbenzotrifiuoride and 1,3-bis-triiluoromethyl benzene.

12 EXAMPLE 16 Preparation of B-chloro-hexafiuoroisopropylbenzenesulphonate Using the procedure described in Example 1, thefollowing materials were applied to the reaction:

Cesium fluoride-37 grams Diglyme (solvent)100 ml.Monochloropentafluoroacetotiegrams Benzene sulphonyl chloride-30.4 cc.

The product was obtained in a yield of 45 grams, B.P. about 240 C. at760 mm. Hg.

EXAMPLE 17 (A) Preparation of Using the procedure of Example 1, thefollowing materials were applied to the reaction:

The product was obtained in a yield of 6 grams, B.P. 105 C. at 1.5 mm.Hg.

(B) Preparation of polymer A portion (5 grams) of the carbonate esterprepared as described above was dissolved in 5 ml. of benzotrifluorideand mg. of a,a-azobisisobutyronitrile was added as a polymerizationinitiator. The solution was heated in a closed vessel at C. for 6 hours,thereby producing a polymer of the carbonate ester, the polymerremaining in solution in the solvent.

EXAMPLE 18 Oiland watcr-repellency of polyacrylates Polymers prepared asdescribed above were dissolved in trifluoromethyl benzene. Solutionsranging in concentration from /2 to 8% were prepared for each polymer.These solutions were then applied to samples of wool fabric by thefollowing method:

The cloth was immersed in the solution to thoroughly wet the cloth withthe liquid. Then, the cloth was passed through squeeze rolls to providea wet pick-up of about The treated fabric was then cured in aforced-draft oven at C. for 20 minutes. After curing, the samples wereweighed to determine the amount of polymer on the fabric.

1 3 The'fabric samples were then subjected to .tests for oilandwater-repellency. The results are tabulated below:

OIL- AND WATER-REPELLENCY TESTS ll Polymers of CH=O H- C-O R Weight ofpolymer on fabric, Oil re- Water re- R percent pellency pelleney--CF(CFa) 2 6. 5 110 100 Same as above. 3. 2 100 100 Do l. 6 100 100 Do0. 8 100 100 Do 0. 4 90 100 /C Fe ---O F 5. 8 100 100 Same as above 2. 6100 100 Do 1. 3 90 100 o 0. 65 80 100 CF(OF2O1)2.. 7.3 0 100 Same asabove.. 4. 1 0 100 0---. 2. 0 0 100 Do 1. 0 0 100 Control (untreated w 00 50-60 It is evident from the above data that all the polymers providedgood water repellency. With regard to oil repellency, the polymer ofheptafluoroisopropyl acrylate provided the best results, whereasreplacement of two fluorine groups by chlorine vitiated theoil-repellent character.

EXAMPLE 19 Durability to laundering of poly-heptafluoroisopropylacrylate The Wool samples treated with poly-heptafluoroisopropylacrylate as described in Example 18 were tested for oilandWater-repellency as initially prepared and after repeated washing by thehome laundering procedure described hereinabove. The results aretabulated below;

Weight of poly- Oil repellency Water repelleuey heptafluoroisopropylacrylate Ini- After 3 After 6 Ini- After 3 After 6 on fabric, percenttial washes washes tial washes washes 6.5 110 110 110 100 100 100 1.6100 90 90 100 100 100 0.8 100 80 60 100 100 90 None (control) 0 50-60EXAMPLE 20 Water repellency of poly-methacrylates Samples of wool clothwere treated with solutions of poly-metha-crylates as described above inExample 18. The water repellency of the products is tabulated below:

WATER-REPELLENOY TESTS 14 EXAMPLE 21 Oil-and water-repellency of CH3 0CF; Polymer of CH2=l-OCH;CHzO-PJO--F The polymer solution prepared asdescribed in Example 17, part B, was diluted further withbenzotrifluoride to prepare solutions at several different polymerconcentrations. These solutions were applied to Wool cloth by immersingthe cloth in the solution, pressing to about 100% wet pick-up and curingin an oven at 110 C. for 20 minutes. The results of oilandwater-rcpellency tests on the products are tabulated below:

Weight of polymer on 0 Water fabric, percent repellency repellencyEXAMPLE 22 In situ polymerization of heptafluoroisopropyl acrylate onwool EXAMPLE 23 Co-polymerization of heptafluoroisopropyl acrylate withn-butyl acrylate Into a 4-02. screw top vial were placed:

4 g. heptafluoroisopropyl acrylate 4 g. n-butyl acrylate 50 mg.u,a'-azobisisobutyronitrile The vial was closed and heated for 2 hoursat 78 C. The copolymer was obtained as a soft, rubbery solid which wassoluble in benzotrifluoride and mixtures of ethyl acetate/benzotrifiuoride. It had an inherent viscosity of 0.9 inbenzotrifluoride at 25 C.

EXAMPLE 24 Preparation and isolation of cesium heptafluoroisopropylateInto a dry, 3-neck round-bottom flask with attached Dry-Ice condenserwere placed 17.4 g. cesium fluoride and 25 cc. tetrahydrofuran. Thedispersion was stirred, cooled in an ice bath (about 5 C.), and 19 g. ofhexafluoroacetone was introduced. After about 10 minutes the alcoholatehad formed as evidenced by the disappearance of CsF. The flask was thenconnected to a vacuum system and the tetrahydrofuran was removed at roomtemperature under 0.1 mm. vacuum. The white, powdery, solid product(cesium heptafluoroisopropylate) remained. Unlike many alcoholates, itdid not appear to be hygroscopic. It was soluble in such solvents asacetone, N,N-dimethylformamide, and diglyme but insoluble in suchnon-polar solvents as n-heptane and chloroform. It appeared to bethermally stable up to about 9O-100 C. At higher temperatures it meltedwith decomposition, evolving hexafluoroacetone.

1 5 Having thus described the invention, what is claimed is: 1. Aprocess for preparing an a-fluoroalkyl ester of an organic acid whichcomprises (a) dispersing an alkali metal fluoride in an anhydrous inertsolvent, (b) cooling the dispersion, (c) adding to the cooled dispersiona ketone of the structure wherein each R is a member of the groupconsisting of hydrogen, halogen, alkyl, haloalkyl, cycloalkyl, andhalocycloalkyl, and wherein at least two of the Rs are fluorine, 90 (d)warming the resulting reaction mixture to about room temperature, (e)without isolating the so-formed intermediate, adding to the reactionmixture an organic acid halide, (f) stirring the reaction mixture atabout room temperature, (g) and recovering the so-produced a-fluoroalkylester having the structure wherein Ac is the acyl radical of an organicacid and R is as above defined. 2. The process of claim 1 wherein theorganic acid halide is a carbonyl halide.

3. The process of claim 1 wherein the organic acid halide is a sulphonylhalide.

4. The process of claim 1 wherein the organic acid halide is ahaloformate.

5. A process for preparing an a-fiuoroalkyl ester of an acrylic-typeacid which comprises (a) dispersing an alkali metal fluoride in ananhydrous inert solvent, (b) cooling the dispersion, (c) adding to thecooled dispersion a ketone of the 0 structure R O I ll CLI2IC CX whereinX is a halogen and R is a member of the group consisting of hydrogen andlower alkyl, (f) stirring the reaction mixture at about roomtemperature, and

(g) recovering the so-produced a-fluoroalkyl ester having the structurewherein R and R have the meaning given above.

67 The process of claim 5 wherein the ketone is hexafluoroacetone, theacid halide is acryloyl chloride, and the product isheptafluoroisopropyl acrylate having the structure 7. The process ofclaim 5 wherein the ketone is hexafiuoroacetone, the acid halide ismethacryloyl chloride, and the product is heptafluoroisopropylmethacrylate having the structure 8. The process of claim 5 wherein theketone is monochloro-pentafluoroacetone (CF COCF CI), the acid halide isacryloyl chloride, and the product is [i-chlorohexafluoroisopropylacrylate having the structure 9. The process of claim 5 wherein theketone is monochloro-pentafluoroacetone (CF -COCF Cl), the acid halideis methacryloyl chloride, and the product is )3-chlorohexafiuoroisopropyl methacrylate having the structure 10. Theprocess of claim 5 wherein the ketone is 1,3-dichloro-tetrafluoroacetone, the acid halide is acryloyl chloride, andthe product is 3,6'-dichloro-pentafluoroisopropyl acrylate having thestructure 11. The process of claim 5 wherein the ketone is 1,3-dichloro-tetrafluoroacetone, the acid halide is methacryloyl chloride,and the product is [3,6'-dichloro-pentafluoroisopropyl methacrylatehaving the structure 12. The process of claim 5 wherein the ketone isperfluoroheptan-4-one, the acid halide is acryloyl chloride, and theproduct is 17 13. The process of claim wherein the ketone isperfluoroheptan-4-one, the acid halide is methacryloyl chloride, and theproduct is (1H3 O (fFg-CFz-C Fa CHz= C*COC F 0 F10 Fz-C F 14. A processfor preparing an a-fiuoroalkyl ester which comprises (a) dispersing analkali metal fluoride in an anhydrous inert solvent,

(b) cooling the resulting dispersion,

(c) adding to the cooled dispersion a ketone of the wherein X is ahalogen and R is a member of the group consisting of hydrogen and loweralkyl,

(f) stirring the reaction mixture at about room temperature, and

(g) recovering the so-produced oc-flllOIOfllkYl ester having thestructure wherein R and R have the meaning given above.

15. The process of claim 14 wherein the ketone is hexafluoroacetone.

16. The process of claim 14 wherein the ketone ismonoehloro-pentafluoroacetone.

17. The process of claim 14 wherein the ketone is 1,3-dichloro-tetrafluoroacetone.

18. The process of claim 14 wherein the ketone is perfluoroheptan-4-one.

wherein each R is a member of the group consisting of hydrogen, halogen,alkyl, haloalkyl, cycloalkyl, and halocycloalkyl, and wherein at leasttwo of the Rs are fluorine, and wherein R is a member of the groupconsisting of hydrogen and lower alkyl.

20. An ester of the structure wherein R is a member of the groupconsisting of hydrogen and lower alkyl.

21. An ester of the structure R o 0 01301 CH2=( Ji )-OGHzOHz-O OCFwherein R is a member of the group consisting of hydrogen and loweralkyl.

22. An ester of the structure wherein R is a member of the groupconsisting of hydrogen and lower alkyl.

23. An ester of the structure wherein R is a member of the groupconsisting of hydrogen and lower alkyl.

References Cited UNITED STATES PATENTS 3,030,409 4/1962 Andreades et a1.260-488 3,274,239 9/1966 Selman 260-514 3,348,939 10/1967 Gier 7l-79Migrdichian: Organic Synthesis, vol. 1, pp. 319-20, Reinhold PublishingCorporation, New York (1957).

ELBERT L. ROBERTS, Primary Examiner D. G. RIVERS, Assistant Examiner US.Cl. X.R.

8115.6; 117-141; 161 UB, 161 UC; 25254.6, 79; 260408, 463, 468 R, 469,471, 473 A, 473 G, 476 R, 484 R, 485 H, 486 H, 487, 488 B, 488 F

